Ceramic knives, imported in increasing numbers during the past 20, years, have attracted much attention in the United States and Europe because of their initial sharpness and durability especially when their use is confined to relatively soft and tender foods. Major drawbacks to their wider use are their tendency to break if dropped on hard surfaces and the lack of a good, convenient and inexpensive sharpener to restore their edge when they become chipped from use.
Several leading manufacturers of ceramic knives have urged users to return chipped blades to their factories in Japan for restoration. One manufacturer went as far as to install sharpening stations in retail outlets as a solution to the sharpening problem but the inconvenience of either means has hindered widespread use of ceramic knives and none of the sharpening stations has demonstrated that it can restore blades to their original factory quality.
Available information suggests that the Asian blade factories sharpen their ceramic blades depending on skilled artisans who place the blade edges in contact with the disks and as a result, the blade edge quality relies heavily on their dexterity, expensive equipment and skill.
Ceramic knife sharpeners supplied by one Asian manufacturer to retail shops to sharpen their ceramic blades was based on extremely high speed disks, using messy liquid abrasive mixtures. Their performance was very inconsistent and customers were dissatisfied with the results.
Even the most recent retail sharpeners offered by the ceramic knife manufacturers do little more than remove major chips from the edge. A battery powered offering uses conventional steel blade sharpening disks and creates a relatively dull edge far inferior to a typical factory edge. Prior to the sharpener described in this application there has not been a ceramic knife sharpener available to the public that can create a factory quality edge on such knives. In fact all sharpeners which have been available created only poor or inconsistent edges.
The present inventors evaluated whether any of the advanced commercially available sharpeners designed for metallic knives could sharpen ceramic knives, only to find they badly chipped the edge of ceramic knives. All such sharpeners tested were totally unusable to produce useful edges on ceramic blades.